Molecular genetic analysis of the Drosophila trithorax-related gene which encodes a novel SET domain protein

Mech Dev. 1999 Apr;82(1-2):171-9. doi: 10.1016/s0925-4773(98)00246-9.


The products of the trithorax and Polycomb groups genes maintain the activity and silence, respectively, of many developmental genes including genes of the homeotic complexes. This transcriptional regulation is likely to involve modification of chromatin structure. Here, we report the cloning and characterization of a new gene, trithorax-related (trr), which shares sequence similarities with members of both the trithorax and Polycomb groups. The trr transcript is 9.6 kb in length and is present throughout development. The TRR protein, as predicted from the nucleotide sequence of the open reading frame, is 2431 amino acids in length and contains a PHD finger-like domain and a SET domain, two highly conserved protein motifs found in several trithorax and Polycomb group proteins, and in modifiers of position effect variegation. TRR is most similar in sequence to the human ALR protein, suggesting that trr is a Drosophila homologue of the ALR. TRR is also highly homologous to Drosophila TRITHORAX protein and to its human homologue, ALL-1/HRX. However, preliminary genetic analysis of a trr null allele suggests that TRR protein may not be involved in regulation of homeotic genes (i.e. not a member of the trithorax or Polycomb groups) or in position effect variegation.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Animals, Genetically Modified
  • Base Sequence
  • Cloning, Molecular
  • Conserved Sequence
  • DNA Primers / genetics
  • DNA, Complementary / genetics
  • DNA-Binding Proteins / genetics*
  • Drosophila Proteins*
  • Drosophila melanogaster / embryology
  • Drosophila melanogaster / genetics*
  • Female
  • Gene Expression Regulation, Developmental
  • Genes, Homeobox
  • Genes, Insect*
  • Homeodomain Proteins / genetics
  • Humans
  • Insect Proteins / genetics*
  • Male
  • Molecular Biology
  • Molecular Sequence Data
  • Sequence Homology, Amino Acid
  • Transcription Factors*


  • DNA Primers
  • DNA, Complementary
  • DNA-Binding Proteins
  • Drosophila Proteins
  • Homeodomain Proteins
  • Insect Proteins
  • Transcription Factors
  • Trl protein, Drosophila